New York

NJ transit goes from Princeton to New York Penn Station. Train schedules can be found here. Adult single costs $16.50. For your convenience, here is a Panda copy of the dinky schedule.

Coach USA runs a bus twice an hour from just outside Fitzrandolph gate to Port Authority Bus Terminal, New York (Central Manhattan). Tickets can be bought at the little kiosk across the road from Fitrandolph gate (that is, in front of J-Crew). Adult single costs $13, Adult round-trip costs $26. NOTE: buying round-trip is recommended, since the Port Authority Bus Terminal has long lines and the ticket booth there (windows 11-15) is far away from the bus stop. The bus stop for Princeton from Port Authority is usually 417; probably better to ask for directions because the building is weird and you can't get to the 4th floor from all parts of the 3rd. Princeton is the last stop on the route (100) so don't worry about missing it, the driver will kick you off.

For your convenience, a page display of the CoachUSA Princeton-New York timetable is available here on Princeton Panda; however, Princeton Panda is not associated with CoachUSA and takes no responsibility for errors.

Philadelphia

NJ Transit goes to Philadelphia 30th Street Station. You have to switch trains in Trenton.

To get to the airport, buy a new SEPTA (Philadelphia's rail) ticket at 30th Street Station. Trains run every 30 minutes. Schedule here: SEPTA.